This patch allows setup Return-path: per virtual host
and thus identify real sender of mail message.  It is
really usefull to identify source of spam and such.

O.

--- php4-4.0.100.orig/ext/standard/mail.c	Mon Jul 30 08:18:06 2001
+++ php4-4.0.100/ext/standard/mail.c	Wed Nov 21 20:44:53 2001
@@ -142,8 +142,10 @@
 #endif
 	FILE *sendmail;
 	int ret;
+	static int sendmail_cmd_len = 0;
 	char *sendmail_path = INI_STR("sendmail_path");
-	char *sendmail_cmd = NULL;
+	char *sendmail_from = INI_STR("sendmail_from");
+	char *sendmail_cmd  = NULL;
 
 	if (!sendmail_path) {
 #ifdef PHP_WIN32
@@ -157,11 +159,18 @@
 		return 0;
 #endif
 	}
-	if (extra_cmd != NULL) {
-		sendmail_cmd = emalloc (strlen (sendmail_path) + strlen (extra_cmd) + 2);
+	if ((extra_cmd != NULL) || (sendmail_from != NULL)) {
+		sendmail_cmd = emalloc (((extra_cmd != NULL)?strlen(extra_cmd)+1:0) +
+			((sendmail_from != NULL)?strlen(sendmail_from)+3:0) + strlen(sendmail_path) + 1);
 		strcpy (sendmail_cmd, sendmail_path);
-		strcat (sendmail_cmd, " ");
-		strcat (sendmail_cmd, extra_cmd);
+		if (extra_cmd != NULL) {
+			strcat (sendmail_cmd, " ");
+			strcat (sendmail_cmd, extra_cmd);
+		}
+		if (sendmail_from != NULL) {
+			strcat (sendmail_cmd, " -f");
+			strcat (sendmail_cmd, sendmail_from);
+		}
 	} else {
 		sendmail_cmd = sendmail_path;
 	}
@@ -171,7 +180,7 @@
 #else
 	sendmail = popen(sendmail_cmd, "w");
 #endif
-	if (extra_cmd != NULL)
+	if ((extra_cmd != NULL) || (sendmail_from != NULL))
 		efree (sendmail_cmd);
 
 	if (sendmail) {